Bitmap -> GIF/PNG/JPG

Ruby
1

Hi,

Can anyone please recommend a package for generating images from a
bitmap vector. e.g. If I have an list of integers, each representing a
colour on the bitmap, and I want to build a GIF from it (along with some
other meta-info like dimensions).

The main options seem to be RMagick and RCairo, but neither seems to
take a bitmap input. I’d have to create a blank canvas and draw each
pixel. Do-able but inefficient.

Thanks,
Michael

2

Michael M. wrote:

Hi,

Can anyone please recommend a package for generating images from a
bitmap vector. e.g. If I have an list of integers, each representing a
colour on the bitmap, and I want to build a GIF from it (along with some
other meta-info like dimensions).

The main options seem to be RMagick and RCairo, but neither seems to
take a bitmap input. I’d have to create a blank canvas and draw each
pixel. Do-able but inefficient.

Check out Magick::Image#import_pixels:
RMagick 1.15.0: class Image (instance methods, part 2). If
the input pixels are in a string buffer this is an extremely fast
method. If the pixel data are in an array it’s still faster than drawing
each pixel separately.

If your pixel data are in a file you may be able to simply describe it
as being in “RGB” or “RGBA” format, in which case RMagick can convert it
for you. See ImageMagick – Image Formats.